Labour has comfortably held the West Lancashire constituency with a 10% swing towards the party in a by-election blow to Rishi Sunak’s Tory party.
It was the first time the Tory vote in the constituency has dipped below 30% since the 1997 general election, which Tony Blair's Labour party won by a landslide.
In a victory speech in the early hours of Friday morning, the newly elected Labour MP Ashley Dalton demanded a general election.
She told the Prime Minister: “Move out of the way. Let Labour take over.”
The new MP added: "Tonight the people of West Lancashire constituency have spoke on behalf of the country.
"They have sent a message to this Conservative Government. They do not have confidence in them to govern or the Prime Minister to lead.
"Prime Minister, your Government has no ideas or a plan to address the big issues facing our country, like record levels of child poverty and people dying waiting for ambulances."
The part-time local charity worker secured a majority of 8,326 over Conservative candidate Mike Prendergast - with a 10.52% swing from the Tories to Labour.
In 2019 Labour retained the seat with a similar majority - but with a 6.8% decline in vote share as the party suffered a disastrous general election defeat.
The Tories vote share plummeted from 36.3% three years ago to just 25.4%.
Turnout on Friday morning was also poor - standing at just 32% - compared to over 71% at the last general election.
Reform UK came third in the poll with 997 votes, ahead of the Liberal Democrats on 918, while the Greens took 646. The Official Monster Raving Loony Party came last, with 210 votes.
Thursday's vote was the final electoral test for both Prime Minister Rishi Sunak and Labour leader Keir Starmer before the May local elections.
Earlier this week, the newly appointed Tory Chairman Greg Hands admitted the party is bracing for a "difficult" set of results.
In the last several months amid turmoil in the Conservative ranks and a bleak economic outlook, Labour has retained a commanding lead in national polls.
The West Lancashire vote was triggered after the resignation of the Labour MP Rosie Cooper who stepped down after 17 years.
She said she was quitting Parliament to become the Chairwoman of the Mersey Care NHS Foundation Trust after a "considerable period of soul searching and reflection".
The ex-MP alluded to the strain of being the target of the failed neo-Nazi murder plot, saying: "The events I have faced over the last few years are well documented and undoubtedly have taken their toll."
Far-right extremist Jack Renshaw was jailed for the plot in 2020 and handed a life sentence with a minimum sentence of 20 years.
Announcing her resignation, Ms Cooper said: “There is no question I am very sad that my time in West Lancashire has come to an end.
"I will leave certain that I gave everything I had to this role which I love, and to people who have come to mean a great deal to me."
More than 149,000 people have now signed the Mirror's petition on the 38 Degrees website calling for a general election now.
